1. Field of the Invention
The present invention relates to a laminated structure, a member for a semiconductor manufacturing apparatus, and a method for producing the laminated structure.
2. Description of the Related Art
Reactive plasma of a halogen, such as F of Cl, for etching or cleaning is used in a semiconductor manufacturing apparatus for use in a dry process or plasma coating in semiconductor manufacturing. Thus, members for use in such a semiconductor manufacturing apparatus require high corrosion resistance and generally include members composed of corrosion-resistant metals, such as aluminum subjected to alumite treatment and Hastelloy, and ceramics. In particular, electrostatic chuck members and heater members for supporting and fixing a Si wafer require high corrosion resistance and low dusting and are therefore made of corrosion-resistant ceramics, such as aluminum nitride, alumina, and sapphire. Even such ceramic materials are gradually corroded in long-term use and generate dust. Thus, there is a demand for higher corrosion-resistant materials. In order to meet such a demand, yttria, which has higher corrosion resistance than alumina, or magnesia or spinal (MgAl2O4), which have still higher corrosion resistance, or composite materials thereof are being studied as materials (for example, Patent Literature 1).
With a decrease in the width of electric wiring, members for supporting and fixing a Si wafer, such as electrostatic chucks and heaters, require excellent temperature uniformity. In order to improve temperature uniformity, it is desirable to use materials having high thermal conductivity. Among the ceramic materials described above, aluminum nitride has particularly high thermal conductivity and excellent temperature uniformity. Aluminum nitride, however, has lower plasma resistance than yttria and has a problem of contamination of electric wiring with dust. Thus, a laminated structure in which a first structure (a corrosion-resistant layer) and a second structure (a substrate layer) are laminated has been proposed (see, for example, Patent Literature 2). The first structure contains a main phase of corrosion-resistant magnesium-aluminum oxynitride. The second structure contains a main phase of aluminum nitride having high thermal conductivity. The corrosion-resistant first structure and the second structure, which has different characteristics (such as heat conductivity and mechanical strength) from the first structure, in the laminated structure can improve corrosion resistance and other characteristics.
[Patent Literature 1] Japanese Patent No. 3559426
[Patent Literature 2] WO 2012/056875